Notholaena nealleyi often has been treated as a variety of the Mexican species N . schaffneri (Fournier) L. Underwood ex Davenport, but recent studies (Windham, unpublished data) suggest that it may represent an allotetraploid hybrid between diploid N . schaffneri and another, as yet unidentified, species. Results of these studies, combined with morphologic differences and geographic isolation, favor the recognition of N . nealleyi as a distinct species.